I usually say something like, “Thanks for sharing the great news! Congratulations!”. If it’s a good friend, I’ll either add something like “Let me know if you need help” or when your schedule permits, let me buy you a celebratory drink” — that way she knows I’m really excited to celebrate this milestone in her life, but it’s low-key enough that she doesn’t feel pressured to add one more thing to her calendar.

“Congratulations! You must be so excited!” is great. Also an offer for a celebratory drink is fabulous but only if you intend on following through! I think asking to see the ring is fine unless of course she isn’t wearing one!

Questions I did NOT appreciate:

When is your wedding? (Um, I just got engaged YESTERDAY I don’t know!)